Dynamic disulfide bonds facilitated fabrication of a multifunctional liquid-free elastomer for recyclable soft electronics

Liquid-free ionic conductive elastomers (ICEs) are of great potential to be used as an ideal alternative to traditional gel materials in soft electronics, with the advantage of the minimum risk of solvent evaporation or leakage under large deformation. Hence, fabricating ICEs with versatile functions of high transparency, self-healing ability, recyclability/degradability, and conductivity as well as mechanical strength is an ongoing pursuit. In this study, we report an ICE constructed from biomass small molecules that meets all the requirements mentioned above. The ICE is synthesized through a facile liquid-free polymerization process, facilitated by the abundant dynamic disulfide bonds and hydrogen bonds present in the small molecular components. This ICE exhibits high transparency (up to 88%), excellent conductivity (similar to 12.8 mS m-1 at room temperature), stretchability (similar to 480%), strong adhesion (322.2 kPa with wood), degradability and full recyclability, and is further utilized as an excellent strain sensor for monitoring human motion and a pressure sensor array. Notably, a touch strip independent of pressure can be constructed by incorporating this material into an AC circuit, boosting its future application prospects in the field of intelligent soft electronics. A liquid-free ionic conductive elastomer constructed from biomass small molecules shows high transparency, self-healing ability, recyclability/degradability, and conductivity as well as mechanical strength.